From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F4BFC433E7 for ; Wed, 14 Oct 2020 22:53:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C33620797 for ; Wed, 14 Oct 2020 22:53:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="Se/mlFeL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729841AbgJNWxS (ORCPT ); Wed, 14 Oct 2020 18:53:18 -0400 Received: from mail.zx2c4.com ([192.95.5.64]:49963 "EHLO mail.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728250AbgJNWxS (ORCPT ); Wed, 14 Oct 2020 18:53:18 -0400 Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 442ae914; Wed, 14 Oct 2020 22:19:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=mime-version :references:in-reply-to:from:date:message-id:subject:to:cc :content-type; s=mail; bh=2bwGM25lN52UQxYKx/Y8jAbUdGU=; b=Se/mlF eLahjhRmIiKnouDoe0+ba694TZ/NJev9yyeuuZGRGjUgc1tYuxRVDaXZrz06s0Hr d/BVx9kGWnNCrcuTyG6uKYR2lrzxf/bZfYpQA2S4y3ZXlDpxbfvuYg8Ov8OW0UV0 s0dv6hhMZRnNcjbloMZnUsXO9M8M0kp16bhFCK2s26LSIp672aXuZbnh7WUZoWRs 0D+vGZS+Y1IbyK51KiCfcZQIzTcVOL+msiHot0nrzxzMHuKcZyi6CNOxLA6S9la6 4Dnx6RGVep3yWF6XRJ1/w5I0XMXZUzlSxWCtdsnMmjvlR+LEY2L0jSEgiWn5EC9v iuNHJlY1xQSHrn3A== Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 830e8d48 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 14 Oct 2020 22:19:41 +0000 (UTC) Received: by mail-io1-f44.google.com with SMTP id 67so1673659iob.8; Wed, 14 Oct 2020 15:53:16 -0700 (PDT) X-Gm-Message-State: AOAM531NBCvdHR+rQRV3wlk/1gmV3m4JR2+FtDn4Zdewd6utotXhT8Zj RbOUl3pC+elhbvSimY7K2n33phkt1HhH5gR3Bpc= X-Google-Smtp-Source: ABdhPJw6bdevPelx8D6A+pUz9BwTRHVh5Qc4DW55dxc0R3DWyvS/aEn/iKmQp/sANsC3zUjJk5FnvAdQ/gv9dzlOT+U= X-Received: by 2002:a6b:3bcf:: with SMTP id i198mr1222193ioa.25.1602715996006; Wed, 14 Oct 2020 15:53:16 -0700 (PDT) MIME-Version: 1.0 References: <20200724012512.GK2786714@ZenIV.linux.org.uk> <20200724012546.302155-1-viro@ZenIV.linux.org.uk> <20200724012546.302155-20-viro@ZenIV.linux.org.uk> <20201014222650.GA390346@zx2c4.com> In-Reply-To: From: "Jason A. Donenfeld" Date: Thu, 15 Oct 2020 00:53:05 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 20/20] ppc: propagate the calling conventions change down to csum_partial_copy_generic() To: Linus Torvalds Cc: Al Viro , Linux Kernel Mailing List , linux-arch , Netdev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Thu, Oct 15, 2020 at 12:51 AM Linus Torvalds wrote: > > On Wed, Oct 14, 2020 at 3:27 PM Jason A. Donenfeld wrote: > > > > This patch is causing crashes in WireGuard's CI over at > > https://www.wireguard.com/build-status/ . Apparently sending a simple > > network packet winds up triggering refcount_t's warn-on-saturate code. I > > Ouch. > > The C parts look fairly straightforward, and I don't see how they > could cause that odd refcount issue. > > So I assume it's the low-level asm code conversion that is buggy. And > it's apparently the 32-bit conversion, since your ppc64 status looks > fine. > > I think it's this instruction: > > addi r1,r1,16 > > that should be removed from the function exit, because Al removed the > > - stwu r1,-16(r1) I just tried that about a minute ago, and indeed that seems to be what's up. Problem goes away without it. I'll send a patch shortly. Jason